Which of the following represents the decreasing order of the rate of electrophilic axomatic substitution?

Question

Question

This question was previously asked in

DSSSB PGT Chemistry (Female) Official Paper (Held On: 06 Jul, 2018 Shift 1)

Answer 1

CONCEPT:

Electrophilic Aromatic Substitution (EAS)

Electrophilic Aromatic Substitution (EAS) is a reaction in which an electrophile replaces a hydrogen atom on an aromatic ring.
The rate of this substitution depends on the electron-donating or electron-withdrawing groups attached to the aromatic ring.
Electron-donating groups (e.g., –OCH₃) activate the ring towards electrophilic attack, while electron-withdrawing groups (e.g., –COOH) deactivate the ring.

EXPLANATION:

The substituents on the aromatic ring can either increase or decrease the electron density of the ring, thereby affecting the rate of electrophilic substitution.
- Electron-donating groups such as –OCH₃ (methoxy) increase the electron density on the ring, making it more reactive to electrophiles and thereby increasing the rate of substitution.
- Electron-withdrawing groups such as –COOH (carboxyl) decrease the electron density on the ring, making it less reactive to electrophiles and slowing the rate of substitution.
In this case, the increasing order of reactivity is:
- - Methoxy (-OCH₃) group (electron-donating) > Carboxyl (-COOH) group (electron-withdrawing)

Therefore, the decreasing order of the rate of electrophilic aromatic substitution is option 2.